Allow `Task` functions in Graphile Worker to return **any** promise type

[1mike12]

Feature description

I noticed that the Task type has a generic already, so Im not 100% sure it's not user error and I'm not typing things correctly. But I want to allow Task functions in Graphile Worker to return any promise type, not just PromiseOrDirect<void | unknown[]>. Right now the Task signature is:

export type PromiseOrDirect<T> = Promise<T> | T;
export type Task<TName extends keyof GraphileWorker.Tasks | (string & {}) = string & {}> =
  (
    payload: TName extends keyof GraphileWorker.Tasks ? GraphileWorker.Tasks[TName] : unknown,
    helpers: JobHelpers
  ) => PromiseOrDirect<void | PromiseOrDirect<unknown>[]>;

which rejects any return value other than void or unknown[]. Since the library treats a resolved promise as success regardless of its return value, the typings should allow arbitrary promise return types (e.g. Promise<number>).

Motivating example

I have a task function that processes a post and patches my database, then naturally returns Objection’s .patch() result (a number):

export async function processItem(
  { itemId }: Payload,
  helpers: JobHelpers
): Promise<void> {
  const item = await Item.query().findById(itemId);

  if (item.status === "pending") {
    await item.$query().patch({ status: "skipped" });
    return;
  }

  if (item.status === "archived") {
    await item.$query().patch({ status: "ignored" });
    return;
  }
...10 more checks
}

This yields:

TS2418: Type of computed property's value is '({postId}: MyPayload, helpers?: JobHelpers | undefined) => Promise<number | undefined>'
  which is not assignable to type 'Task<any>'
Type 'Promise<number | undefined>' is not assignable to type 'PromiseOrDirect<void | unknown[]>'

Yet Graphile Worker itself ignores the resolved value and only cares about thrown errors. Allowing Promise<T> would remove friction and better reflect how users actually use async tasks.

Breaking changes

None for runtime behavior. Typing changes will be backward-compatible for existing tasks that return void or unknown[], but consumers who currently rely on the narrower return type might need to adjust. Bumping to a new minor or major version may be appropriate.

Supporting development

I [tick all that apply]:

• am interested in building this feature myself
• am interested in collaborating on building this feature
• am willing to help testing this feature before it's released
• am willing to write a test-driven test suite for this feature (before it exists)
• am a [Graphile sponsor](https://www.graphile.org/sponsor/) ❤️
• have an active [support or consultancy contract](https://www.graphile.org/support/) with Graphile

---

[benjie]

https://worker.graphile.org/docs/typescript#assuming-type-via-graphileworkertasks

[benjie]

Wait… what do you mean return a value? Where would it go? There’s a reason we enforce void: it doesn’t go anywhere so there’s no point returning anything from it… unless I’m missing something?

[benjie]

Are you saying you don’t want to do an await followed by a return as separate statements? Have you considered return void await thing()?